Magnetic separator



3 Sheets-Sheet l L( d. VCczl lo( Lune I 1 CATTonNaY-r vAug. 14, 1951 H. J. CALDWELL MAGNETIC SEPARATOR Filed'M-amh 1, 1947 Aug. 14, 1951 H. J. CALDWELL MAGNETIC SEPARATOR 3 Sheets-Sheet 2 Filed March l, 1947 Aug 14, 1951 H. J. CALDWELL 2,564,593

MAGNETIC SEPARATQR Filed March l, 1947 3 Sheets-Sheet 5 UIT-roaNEY-J Patented ug. 14, 1951 MAGNETIC SEPARATOR Harry J. Caldwell, Rockford, Ill., assignor to Barnes Drill Co., Rockford, lll., a corporation f Illinois Application March 1, 1947, Serial No. 731,854

(Cl. B-1.5)

Z Claims.

The invention relates to the removal of foreign material from liquid coolant used in machining operations and more particularly to apparatus for treating the liquid coolant used in abrading operations to remove entrained metal and abrasive particles generally known as swarf therefrom.

One object of the invention is to provide unitary coolant treating apparatus of the above general character adapted to handle the liquid coolant used by a plurality of abrading machines and capable of operating continuously for long intervals without requiring periodic stops for cleaning or the like.

Another object is to provide a large capacity coolant treating apparatus which requires a mini-` mum of shop floor space for its installation and which is capable of thoroughly and efficiently reconditioning large volumes of liquid coolant for use at a minimum cost per unit volume of the uid treated.

It is also an object of the invention to provide coolant treating apparatus which by reason of its novel unitary construction can be produced economically in varying sizes to meet the requirements of a Wide variety of shop conditions.

Other objects and advantages of the invention will become apparent from the following detailed description of the preferred embodiments in which: A

Figure 1 is a partly sectioned end view of coolant treating apparatus embodying the features of the invention;

Fig.2 is a partly sectioned side view of the apparatus;

Fig. 3 is a transverse sectional view of a modifled form of coolant treating apparatus; and

Fig. 4.- is a longitudinal sectional view of the apparatus taken in a vertical plane substantially on the line 4-4 of Fig. 3.

While the invention is susceptible of various modifications and alternative constructions, I have shown in the drawings and will herein describe in detail the preferred embodiment, but it is to be understood that I do not thereby intend to limit the invention to the specific form disclosed, but intend to cover all modifications and alternative constructions falling Within the spirit and scope of the invention as expressed in the appended claims.

In accordance with the invention, the improved apparatus, While relatively small and compact, is enabled to eiciently and thoroughly treat a large volume of liquid coolant by incorporating therein a plurality of continuously rotating magnetic drums IIJ arranged in a novel manner to facilitate the flow of coolant through the apparatus and the removal of the swarf therefrom. More particularly, the magnetic drums are arranged in vertically and laterally spaced relation with suitable channels for delivering the coolant to and circulating it around the several drums and for continuously removing the swarf Withdrawn from the coolant.

The magnetic drums I0 are preferably of the type disclosed in my copending application, Serial No. 710,564, filed November 18, 1946, now Patent No. 2,541,202. As herein shown, each drum comprises a hollow cylindrical shell II (Fig. 1) of nonmagnetic material closed at opposite ends by heads I2 keyed or otherwise nonrotatively secured to a shaft I3 of sufcient length to project at each end of the drum. Within the shell II a plurality of permanent magnets I4 of Alnico or the like are arranged in circumferentially spaced rows with their poles disposed closely adjacent the shell. The arrangement is such that the particles of magnetic material entrained in the coolant circulated around the drums together with a substantial part of the entrained abrasive particles are collected on the surface of the drum. The collected particles are withdrawn from the coolant by rotation of the drum and may be removed therefrom in any preferred manner.

The particular `coolant treating apparatus illustrated is provided with four of the drums I0 arranged with their axes horizontal and in a generally rectangular formation, that is, with one pair of drums above the other, the drums of the respective pairs being spaced apart laterally. The drums In are rotatively supported in a rigid frame structure I5 including upright members I6 and I'I (Fig. 2) having suitable bearings I8 for receiving the ends of the shafts I3.

Coolant to be treated is directed into operative relation to the drums Ill through main and branch channels formed by members constituting, in this instance, a part of the frame structure I 5. The channel forming members include a pair of elongated flat plates 2U and 2| extending substantially horizontally between the upright plates I6 and I1 and respectively having downwardly and outwardly projecting arcuate extensions 22 and 23 at opposite sides. The member 20 is disposed between the lower pair of drums II! and the member 2| similarly disposed between the upper pair of drums with their arcuate extensions 22 and 23 partially encircling the adjacent drums.

As will be seen by reference to Fig. l, the inner edges of the arcuate members 22 and 23 are extended somewhat above the upper surface of the associatedy members 20 and 2|, thus forming shallowchannelsjiid and' 25 for directing the flow of liquid coolant longitudinally of the apparatus. Moreover, the arcuate members 22 and 23 are spaced from the peripheral surfaces of the associated drums I so as to form therewithelohgated shallow channels 26 and 21opening from the main channels 24 andi25`and serving to-gli rect the coolant flow over a substantial Iportion of the surface of each drum. The arcuate members are desirably constructed of `magnetma-q terial and serve as shunt plates for concentrating the fields of the magnets I4 within the channels 23 and 21. The magnets are thus enabled to attract the entrained foreignparticles from the coolant to-.thesurfacelofthe associated drums.

vTo ensure a cwbf coolant through the branch channels,.the outer .edges of the arcuate members 22 and -23 are terminated in horizontal planes spaced slightly .below the `planes of the inner edges of the members. In the particular apparatus shown, the inner edges of the members are located slightly above the central axes .of .the associated drums while the vouter edges of the members Vare terminated belowrsuch axes.

By reason of the above construction, the coolant undergoing treatment flows from the main channels 24 and 25 Ythrough .the branch channels 25 and 21 and is discharged over theouter edges of the arcuate members v22 and 123. In the passage of the coolant through the branch .channels, the foreign material .is attracted to .and held on the surfaces ofthe .drums .I0 .and the clean coolant is discharged into 4trough-like channels 30 formed by suitable partitions in the frame structure. The clean coolant is/then directed through vertical passages -3I (Fig. 2) at .one end of the frameto va suitabletank or reservoir from which it Amay be withdrawn for reuse as required. As herein shown, the passages .3| are formed in the frame/structure by the upright plate I1, an end plate 32 spaced `therefrom and the side walls of the frame. Openings v33 in the upright plate I1 provide communication between the channels 3B and the passages Y3 I.

-Liquid coolantto be treated `by the apparatus is received in a shallow .tank 35 .mounted in .the frame structure I andcommunicating with the main channels 24 and 25 through avertical passage 36 at one end Vof the frame. The passage 36 in this instance vis defined by a generally V-shaped partition .31 interposed between :the upright plates I1 and 32, as shown-in Fig. l.

To avoid objectionable splashing of lthe Aliquid coolant ,and to insure uniform ldistribution of the same through the branch channels 2.5 and 21, fluid is delivered to the main channelsthrough tubes or pipes Y3.8 vand 39 located above and .extending longitudinally of the said-main channels. '.Ihe pipes are open at one end to the .passage 3 5 and .are Aformed with downwardly facing longitudinal slots v`III) through which the liquid is discharged into the channels. The 4slots are preferably dimensioned so as to yrestrict the flow of V suitable character.

' he upright plate e coolant to a rate within the capacity of the branch channels, thus effectually preventing overflow of coolant in the event of momentary increases in the rate of delivery to the apparatus.

To provide for uninterrupted operation of the apparatus, provision is made for rotating the magnetic drums IU continuously whereby the sWarf collected thereon is withdrawn from the branch channels 24 and 25 and discharged into suitable hoppers il located'outside of the frame structure. In the exemplary apparatus, the drums are rotated by Aa common drive mechanism including an electricmotor Mand speed reducing transmissionI which maybe of any The motor and transmission are supported on the outer face of an up- .rightzplate 42 closing one end of the frame as The plate 42 is spaced from vIii-to form a compartment 43 enclosing Ytlfiatgpart of the drive mechanism interposed between the drums I9 and the transshown in ^Fig. 2.

fmissien FI.

As will be seen by reference to Fig. 2, the transmission T has its terminal shaft 44 projecting into the chamber d3'. The terminal shaft car- -ries a sprocket wheell 45 Fig.-.l) fior. [cooperation .sprocket A-vv-heels .475 rigid with the v:companion drums Ill and over an idler `sprocket 48 `supported-in `the samemanneras the sprocketA. Due Yto the gear Yconnection between-the terminal shaft M and the intermediate shaft 50,-the Vdrums at the right side of the frame .-arerotated in a direction opposite vto the directionof rotationof `the other drums orclockwise-as `viewed in fFig. `1.

Means is provided `for 'removing collected swarf from the magnetic drums IIJ incident to their rotation and for discharging it into `the hoppers M. For this purposereachdrum:isprovided-with V.an -individual scraper blade 55 having one edge bearing against the surface of the. drum. As yherein Vshown, the .blades 155 are. carried :by inclined spout membersi fmountedin .the-frame and proejcting laterally therefrom .above the hoppers A I.

To facilitate disposal of the swarf, eachofithe hoppers 4I .is ,preferably equipped with means for conve-ying .the vcculected .swarf to :a suitable discharge outlet. The conveying means, asherein shown, comprises anelongatedscrewhaving a shaft B0 journaled insuitable bearings atopposite ends `of .the hopper. The screw-is kdriven continuously by means tof a chain lil ,running over a Sprocket `1512 .o n fthe ,screw Shaft .50 and .a driving sprocket 6 3 carried l.by the .shaft :L3 of the lowermostgvdrum of itheadjacentpair.

IIn the particular apparatus shown. .the Conveyor yenclosing Aportion Qf the hopper k4.1 :1S feX- tended beyond the endgf the frame Structure l5 and is provided .with .a `film/.twvaH2115' opening ldischarge tube G4 through which-the collected-syvarf may .be discharged into a removable container 65. To ensure an effective flow of the swarf, the discharge tube is provided with suitable feed mechanism driven from thegconveyor Screw by' gearing 66 and a chain and sprocket connection 61.

In operation, a continuous ow of liquid coolant through -the apparatus may be maintained for long periods without` interruption for cleaning or the like. The untreated coolant enters the apparatus by way of the receiving tank 35 and after circulating through the passage 36, main channels 24 and 25 and branch channels 26 and 21, it is delivered thoroughly cleaned and conditioned for reuse through the channels 30 and the passage 3|. The particles of foreign material or swarf entrained in the coolant is collected on the magnetic drum I0 and withdrawn from the coolant in a continuous operation. Such collected swarf is scraped from the drums and discharged into the hoppers 4I from which it is conveyed to suitable containers so that it may be removed without interrupting the operation of the apparatus. Thus liquid coolant used in abrading or other machining operations may be reconditioned for use in large quantities and at minimum cost.

In the modified form of coolant treating apparatus shown in Figs. 3 and 4, a pair of the magnetic drums l0 are supported horizontally in laterally spaced relation in an elongated frame l0. The outer side walls of the frame are shaped to provide a pair of main ilow channels 'Il and 12 extending longitudinally of the frame parallel to the respective drums. Arcuate members or plates 13 and 'i4 of magnetic material extend inwardly from the sides of the frame and partially encircle the drums ID to form therewith shallow branch channels 'I5 and 'I6 by which the coolant from the channels 'H and 12 is directed into operative relation with the drum surfaces. Coolant discharged from the inner ends of the branch channels 'l5 and 16 is caught in a central channel 'Il by which it is delivered to a suitable tank or reservoir for reuse. As shown in Fig. 3, the channel 'I1 is formed by a troughshaped member 18 extending longitudinally of the frame structure between the drums l0.

Suitable drive mechanism is provided for continuously rotating the drums l0 to Withdraw the collected swarf from the coolant. The drive means in its preferred form includes a motor M1 mounted at one end of the frame and having a chain and sprocket driving connection 88 with a shaft 8l journaled in a bracket rigid with the frame. The shaft 8l in turn drives a transverse shaft 82 through the medium of a worm 83 cooperating with a worm wheel 84 keyed to the latter shaft. The shaft 82 is provided with a pair of worms 85 coacting with worm wheels 86 keyed to the supporting shafts I3 of the respective magnetic drums. One of the worms 85 is preferably formed with a left-hand thread while the companion worm is formed with a right-hand thread, thus serving to rotate the cylinders IU in opposite directions. In the particular apparatus shown, the drum l@ at the left of the frame (as viewed in Fig. 3) isdriven in a clockwise direction while the companion drum is rotated counterclockwise. For removing collected swarf from the drums Ill, each drum is provided with an elongated scraper blade 81 ybearing against its periphery. The scraper blades 8l are secured to and supported by the side walls of the V-shaped trough 88 extending longitudinally of the frame l0 between the two drums. Thus as the drums rotate 6 the swarfis scraped o and discharged into the trough.

To permit continuous operation of the apparatus, the trough 88 is equipped with a screw conveyor 89 adapted to convey the collected swarf to a suitable discharge outlet. The screw conveyor may be driven from the shaft 82 through the medium of a worm 90 keyed thereto and cooperating with a worm gear 9|, keyed to the conveyor shaft. In the particular machine illustrated, a second conveyor 92 (Fig. 4) is provided for carrying the swarf from the screw conveyor 99 to suitable disposal receptacles.Y To this end, the screw conveyor is arranged to discharge the collected swarf into a housing 93enclosing the conveyor 92, herein shown as a belt type conveyor. The housing 93 is supported, in this instance, by a bracket 94 at one end of the frame 18, the bracket also having a bearing 95 for supporting the outer end of the conveyor screw 89.

It will be apparent from the foregoing that the invention provides apparatus of a novel and advantageous character for treating the liquid coolant used in abrading operations to condition the coolant for reuse. The improved apparatus is particularly well adapted for handling large quan. tities of liquid coolant and is capable of operating for extended periods without interruption for cleaning or other purposes. The unitary character of the construction, in particular the use of a plurality of similar magnetic drums, makes it practicable to construct the apparatus in various sizes to meet the requirements of different installations. V

I claim as my invention:

l. Apparatus for removing swarf from liquid coolant used in abrading operations comprising, in combination, a frame, a pair of magnetic drums rotatably supported on said frame with their rotational axes horizontal and spaced apart laterally, means rigid with the frame forming coolant flow channels extending along the outer sides of the drums, arcuate frame members cooperating with said drums to form branch channels extending from said main channels and partially encircling said drums, frame members forming a trough shaped channel extending longitudinally of the frame between said drums for receiving the coolant passing through said branch channels, a trough shaped member extending longitudinally of the frame above said trough-shaped channel, outwardly-directed scraper blades carried on the side Walls of said trough-shaped member cooperating with the respective drums and operative during rotation of said drums to remove collected swarf therefrom, a screw conveyor extending longitudinally of said trough shaped member, and a power driven transmission supported at one end of the frame for rotating said drums in opposite directions to move the peripheries thereof into contact with the respective outwardly-directed scraper blades, and for driving said screw conveyor to remove collected swarf from said trough-shaped member.

2. Apparatus for removing magnetic particles from liquid coolant used in abrading operations comprising, in combination, a frame, a pair of magnetic drums supported on said frame for rotation about horizontal laterally-spaced axes, frame members forming coolant ow channels extending along the outer sides of the drums, other frame members forming branch channels extending from said first-mentioned channels and partially encircling said drums, still other frame members dening a trough-like channel '7 donated betweeiizsaid @drums "forwrreceiving-i coolant passing through said branch channels, amopper located f ybetweenl ssaidaditums fin"vertically-spaced relation above sa-id trough-like *chamielgoutwardlyridireoted sonaeper .blades "cooperating with the f respectiveA drums Aadj ement-.their inner'.:sidesfl and operative :.rduririg :rotation of saidf-:drums to remove i bhe :collectedgpari'licles: from thegperipheries i thereof; and to deposit-said rparticlesin -sagidihop- 41er,1 means'coopenating-withfsaid hopper io re-f moine @collected vsvxzarf `therefrom, --fand a power'- sdriven `transmission cpenativfe to rotatasaid drums in :opposite directions zto '.move i .the ..peri-pheries thereof :into Contact Awith thenrespective out- -`wardlyeclirected scraper blades.

'AI'I'ARIHLJ.- 

